Staged air burner with swirling auxiliary air flow

ABSTRACT

A chamberless, high intensity staged air burner especially suited for the incineration and combustion of contaminated fuels and waste streams by achieving a high, concentrated degree of mixing and, therefore, a high temperature, in a relatively small but structurally unconfined volume. The burner utilizes the principle of vortex air flow from an air induction chamber together with swirling auxiliary air flow to achieve a high degree of recirculation local to the point of fuel injection, to provide intimate mixing of fuel and air, precise control over the flame envelope. Utilizing the air required for combustion in the foregoing manner eliminates the need for a refractory-lined chamber which otherwise would be required to confine the combustion process in order to generate the extreme temperatures sometimes required for complete incineration. The swirling auxiliary air flow is obtained by providing a plurality of circumferentially arranged swirl vanes in way of the portion of inlet air directed through the auxiliary air passageways. These swirl vanes may be mounted for limited movement or can be stationarily secured in the desired position.

United States Patent 1 Guerre et al.

[ 1 STAGEI) AIR BURNER WITH SWIRLING AUXILIARY AIR FLOW [75} Inventors:Robert P. Guerre, Dover;

Ross R. Ruland, Hopatcong, both ofNJ.

[73 l Assignee: Esso Research and Engineering Company [22] Filed: Jan.12, 1972 [2]] Appl. No.: 217,349

Related U.S. Application Data [63] Continuation-in-part of Ser. No.52,341, July 6, 1970,

Pat. No. 3,671,173.

[52] U.S. Cl. 431/182 [51] Int. Cl. F23m 9/08 [58] Field of Search431/182, 183, 185, 431/188 [56] References Cited UNITED STATES PATENTS2,219,696 10/1940 Mueller et al. 431/185 X 3,208,502 9/1965 Carlson....431/188 3,301,305 1/1967 Kimmel 431/183 X 3,226,038 12/1965 Brady et al.431/183 Primary Examiner-Edward G. Favors Attorney- Leon Chasan, F.Donald Paris et al.

[ 1 July 17, 1973 [57] ABSTRACT A chamberless, high intensity staged airburner especially suited for the incineration and combustion ofcontaminated fuels and waste streams by achieving a high, concentrateddegree of mixing and, therefore, a high temperature, in a relativelysmall but structurally unconfined volume. The burner utilizes theprinciple of vortex airflow from an air induction chamber together withswirling auxiliary air flow to achieve a high degree of recirculationlocal to the point of fuel injection, to provide intimate mixing of fueland air, precise control over the flame envelope. Utilizing the airrequired for combustion in the foregoing manner eliminates the need fora refractory-lined chamber which otherwise would be required to confinethe combustion process in order to generate the extreme temperaturessometimes required for complete incineration The-swirling auxiliary airflow is obtained by providing a plurality of circumferentially arrangedswirl vanes in way of the portion of inlet air directed through theauxiliary air passageways. These swirl vanes may be mounted forlimited'movement or can be stationarily secured in the desired position.

16 Claims, 8 Drawing Figures Pmmm JIJU 1 ma sum 1 or 3 :IE 1

PAIENIED- 1 m1:

SHEET 2 [IF 3 STAGED AIR BURNER WITH SWIRLING AUXILIARY AIR FLOWCROSS-REFERENCE TO RELATED A PPLICATIONS This application is acontinuation-in-part of copending U. S. Patent Application Ser. No.52,341, filed July 6, 1970, now Pat. No. 3,671,173 and assigned to theassignee of the present application. The new subject matter containedherein is directed the swirling nature of the auxiliary or secondary airflow and the structure associated therewith for accomplishing the samein combination with a chamberless high intensity vortex burner such asdisclosed in Ser. No. 52,341, which is herein incorporated by reference.

BACKGROUND OF THE INVENTION 1. Field of the Invention In general thepresent invention relates to chamberless, high intensity vortex burnersof the staged air type and more particularly to a novel and improvedvortex burner which employs swirling auxiliary air flow.

2. Description of the Prior Art Typical prior art high intensityconstruction burner constructions generally include some sort ofcombustion chamber which is required to contain and confine the burningprocess to achieve a high degree of mixing and completeness ofcombustion. The heated walls of the combustion chamber aid in thecombustion process by radiating heat from the chamber walls back towardthe flame. These walls or a choke-type throat construction aid incontainment and shaping of the flame by restricting the tendency of thegases to expand and limiting the flames radial expansion.

Heretofore, prior art burners have employed secondary swirling air, suchas disclosed in U. '8. Pat. No. 3,301,305. However, the construction,arrangement and operation of these typical prior art burners difierssufficiently from the present invention so as to make the resultsobtained by the present invention unobtainable in the prior art. Suchprior art constructions are not designed so that combustion can'occur inthe absence of a combustion chamber.

SUMMARY OF THE INVENTION of recirculation local to the point of fuelinjection.

In accordance with the present invention there is provided a novel andimproved construction for high intensity burners wherein the need for acombustion chamber is completely eliminated by virtue of the employmentof auxiliary air stream flow to control, contain and shape the flameenvelope and simultaneously provide adequate turbulences for therequired air/fuel mixing. By imparting a swirl or spin to the auxiliaryair flow the tendency of the primary vortex air flow is restricted,which results in improved ability of the burner to control and shape theflame envelope, as. well as enhancing the air/fuel mixture. Theauxiliary air flow may be spun in the same general direction as thevortexing primary air flow or in a countercurrent direction thereto. Theburner is constructed and arranged such that the inlet air stream flowsin predetermined precise part through the swirl chamber while theremaining portion of the inlet air stream flows through one or moreauxiliary passageways or gaps provided so that the secondary orauxiliary air flow will shape the flame inwardly to control itsexpansion, restrain the limits of flame expansion and to keep thecontaminated fuels off the small amount of refractory surrounding thegap so as to maintain the integrity of the refractory. The momentum ofthe air flow through the gap is sufficient to enable it to mix with thefuels so that complete combustion is achieved within a short distancerelative to the point of fuel injection, thereby to provide a relativelysuperior, shorter flame which obtains a reduction in flame impingement.A plurality of swirl vanes are provided in way of the air gap in orderto impart a spinning or swirling motion to the secondary air flow and tocontrol the rate of secondary airflow. Throughout this disclosure theterm primary air flow is intended to mean that air closest to the fuelsupply. The terms secondthe air flow(s) other than the primary flow toaccomplish the results outlined above. The important characteristic tokeep in mind throughout this invention is that the gap air flow must bethe dominant factor, that is, it must be sufficiently strong to resistexpansion of the vortex flow, which according to the present inventionfunctions to stabilize the flame and tip only. Thus, it is apparent thatat least percent of the air flow must be through the gap(s).

In the preferred embodiment of the invention preferably only a singleauxiliary air flow is employed to obtain the desired flame quality. Theprimary air flow is utilized to create a vortex flow region in theimmediate vicinity of the fuel supply, which may comprise an oil or gasgun. This characteristic of the burner is essential for good flamequality and stability, especially when utilizing heavy oils. Theremainder of the inlet air flow enters through an annular gap disposedabout the vortex air flow inducing means to control the limit ofexpansion of the flame and to create the desired pattern of hotgas/flame envelope and thus, the burner requires no combustion chamber.Although either preheated or ambient inlet air may be employed, by usingpreheated inlet air a relatively small amount of gap air flow bouncesoff the fuel rich mixture it is designed to intersect with, thusobtaining the desired combustion and permitting the use of only a singleair gap. It is within the scope of this invention, however, to employmultiple air gaps such as disclosed in applicants aforementionedcopending application. According to the present invention the refractorymaterial which is located below the air gap is subjected to a vortexwash plus a sub-stoichiometric air/fuel ratio (that is, a fuel richmixture) so that the temperature thereof is relatively low so as toobtain relatively little heat release along its surface and therefore,the refractory has a relatively high life expectancy even whenrelatively bad fuels are employed. The vortex wash aids in cooling therefractory surface and is insufl'icient to obtain combustion until theair/fuel mixture is contacted by the auxiliary air flow. Typical of theadvantages flowing from such the lack of the necessity for a refractorycombustion chamber, which means that even under the worst conditions, anonexistent refractory cannot be deleteriously affected. In general, theoverall construction is simplified since it is not as sensitive toaerodynamic ratios as is true in prior art situations discussedheretofore.

Accordingly, it is a primary object of the present invention to providea novel chamberless high intensity vortex burner employing auxiliary airflow.

Another object of the present invention is to provide a novel andimproved chamberless, high intensity vortex burner which retains theadvantages of present day superior high intensity burners, whileeliminating the need for a combustion chamber by utilizing the principleof air stream momentum to control and contain the flame envelope.

A further object of the present invention is to provide a chamberlesshigh intensity burner which utilizes a predetermined portion of theinlet air flow to create a vortex flow region in the immediate vicinityof the fuel supply and includes at least one annular gap locatedproximate the vortex region to provide a passageway for an auxiliaryswirling air flow to control the limit of expansion of the flame.

Having in mind the above and other objects that will be evident from anunderstanding of this disclosure, the invention comprises theconstruction and arrangement as illustrated in the presently preferredembodiments of this invention which is hereinafter set forth in suchdetail as to enable those skilled in the art readily to fully understandthe function, operation, construction and advantages of it when read inconjunction with the accompanying drawings in which:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective viewof a preferred embodiment of a chamberless high intensity burnerconstructed and arranged in accordance with the present invention;

FIG. 2 is a vertical-sectional view of the burner of FIG. 1 takensubstantially along the line 22 of FIG.

FIG. 3 is a horizontal-sectional view taken substantially on the line3-3 of FIG. 2;

FIG. 4 shows a portion of FIG. 3 with the vanes moved clockwise from theposition shown in FIG. 3;

FIG.-5 is a cross-sectional taken substantially on the line 5--5 of FIG.4;

FIG. 6 is a cross-sectional view of the vane and guide pins takensubstantially on the line 6-6 of FIG. 4;

FIG. 7 is a cross sectional view of the push rod taken substantially onthe line 77 of FIG. 4; and

FIG. 8 is a perspective view of a vane constructed and arrangedaccording to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Having reference to the drawingswherein similar parts are designated by like reference numerals, FIGS. 1through 8 illustrate in detail a preferred embodiment of the presentinvention. In FIG. 1 there is shown a chamberless high intensity vortexburner generally designated l0 maintained in a furnace floor or wall 11by suitable welds or brackets (not shown). The burner comprises acylindrical open-ended burner casing 12 (see FIG. 2) made of carbonsteel construction and lined internally with a block type insulation 13secured to the interior of the casing 12 by a suitable insulationadhesive. When preheated air is employed the insulation 13 providesprotection against a person inadvertently touching the hot casing. Thecasing 12 includes a radially disposed air duct 14 for providing aninlet opening 15 to receive the air flow designated by the arrow, whichmay be ambient or preheated. Preheated air, if employed, may be suppliedby conventional means (not shown) such as a standard air preheated orother suitable type of conventional preheater.

The casing 12 is provided at its bottom with a cover plate 16. A blockinsulation 17 is secured to the interior surface of the cover plate 16.The cover plate 16 extends radially outward beyond the intemalinsulation 17 to provide an apertured flange 18 which facilitatesmounting of the cover plate 16 to the burner casing 12 by means of nutsand bolts generally designated 19, as shown in FIG. 2. The cover plate16 is formed with a central opening 20 having a packing sleeve 21disposed therein for mounting air flow inducing means including a casing22 of conventional construction in an air inlet plenum chamber 23, forreceiving a predetermined portion of the inlet air flow. The air flowfrom the plenum chamber flows in two directions. One flow is tangentialthrough the tangentially arranged air ducts 24 such that the inlettangential air flow through the cham' her or casing 22 is modified toinclude an axial direc tion component of vortex air flow. The other airflow is a secondary or auxiliary air flow through the air gap asdescribed hereinafter. The chamber 22 is mounted conventionally as bestillustrated in FIG. 2, which also illustrates the general air flowpattem. The chamber 22 has associated therewith an upper radiallyextending annular seat or support plate 25 (located above the ducts 24).The plate 25 includes a plurality of radially spaced apertures 26 spaced90 apart. An annular primary or lower burner tile 27 made. of asuitable, high temperature castable refractory material seats on thesupport plate 25 and may be secured thereto by a suitable refractorycement and restrained radially by peripherally disposed upstanding metalclips 28 (see FIG. 2) welded to the plate 25. The upper surface of theprimary burner tile 27 has a substantially pyramidal shape comprising aninner outwardly sloping surface 29 joined to form an apex with an outerinwardly sloping surface 30. A centrally open annular floor plate 31 isprovided with downward extending threaded bolts or mounting rods 32 forpressing through corresponding ones of the apertures 26 to mount thesupport plate 25 at a distance which is adjustable relative to the floorplate 31. Thus, the primary burner tile 27 also is verticallyadjustable. The members 25 and 31 are fastened by means of conventionalnuts which thread onto the threaded portion of the rods 32 extendingthrough the I apertures 26. The floor plate 31 has secured thereto by asuitable refractory cement or the like, a secondary or upper annularburner tile 33 which is also made of a high temperature castablerefractory material. The tile 33 has an inner annular surface ofpyramidal shape comprising an upper annular surface 34 having a slopesubstantially similar to and when mounted coplanar with the surface 29,and a bottom or lower annular surface 35 whose slope is parallel withthat of the surface 30 and is disposed in spaced parallel relation tothe surface 30 as shown in FIG. 2. When mounted as shown in FIG. 2 thesurfaces 35 and 30 form a continuous uni form annular air gap 36. Thewidth of the gap or auxiliary air passageway 36 may be adjusted bychanging the vertical disposition of the support plate 25 relative tothe floor plate 31. By closing the air gap the velocity of the auxiliaryor secondary air flow may be controlled, that is, made greater byclosing the gap or lessened by making the gap wider.

Typically, in operation, a predetermined precise portion of the inletair flow enters through the air ducts 24 of the casing 22, for example25 to 50 percent, which comprises the primary air flow and creates astrong vortex flow which forces the hot gases to recirculate back to thefuel spray, which enters through the fuel gun shown in partschematically in dotted lines by reference character 37, thus heating itand aiding in combustion. The remaining 50 to 75 percent of the inletair flow enters through the continuously uniform annular air gap 36.This auxiliary or secondary air flow shapes the flame inwardly tomaintain the contaminated fuels off the surrounding refractory material,and further produces a high turbulent zone for mixing the fuel and airto achieve complete combustion within a relatively short distance of thefuel gun. By imparting a swirling or spinning motion to the secondaryair flow, in the manner as described hereinafter, the tendency of theprimary vortex air flow to expand radially upon exiting is restrictedwhich goes toward improving flame quality. This secondary swirl may becountercurrent to the direction of helical primary vortex air. Thus, thevortex air flow achieves a' high degree of recirculation local to thepoint of fuel injection together with one or more coaxially disposedannular-shaped streams of air to provide intimate mixing of fuel andair, as well'as to shape, control and contain the flame envelope. Airflow through the annular gap 36 controls the limit of expansion of theflame and creates the desired pattern of hot gas/flame envelope. Thefuel supply may comprise conventional means 37 such as a center firedgas gun unit or a standard oil gun. The burner is provided with theusual pilot guide tube (not shown) and pilot light-off tube (not shown).Extending through the central opening 20 of the cover plate 16 is abottom flanged gun guide tube 38, which is received in the sleeve 21.

In the event that the preferred embodiment utilizes preheated air, atypical temperature range of the air would be about 500 750F. Since airis the main force in this burner construction, its flow must bemaintained in a substantially uniform manner. Essentially this meansthat any obstruction such as coke deposit, refractory pieces or lowpressure may cause'an unbalancing of the flame and thereby createfurther overheating or additional deposits to one side or the other ofthe burner so that eventually the entire burner may fail. Accordingly,the present burner has been constructed and arranged so thatinterference with air flow is minimized. It is most desirable tomaintain the annular gap 36 uniform as any non-symmetry will cause theflame to lean more so toward the favored'side.

To impart the spinning or swirling motion to the secondary air flow,there is provided a plurality of swirl vanes 39. As shown in FIGS. 1through 3 these vanes 39 are disposed in way of the entry to thesecondary air gap 36 and are oriented such that they spin the secondaryair flow in the desired direction. In the preferred embodiment, thevanes are mounted on a rotatable plate 40 which is designed to sit onthe support plate 25 between the radially spaced mounting rods 32. Thesemounting rods effectively function as guides for the plate 40 in theevent that the plate is moved in order to change the disposition of thevanes 39. The plate 40 is thus prevented from undesirable inward andoutward radial movement. Each of the vanes 39 comprises a rectangularshaped elongated portion 41 and located at one end thereof a tubular orbored member 42. The elongated portion 41 either may be welded to thetubular member 42 or the vane may comprise a single piece of metalroll-formed into the desired configuration. Circumferentially disposedabout the rotating plate 40 at about thirty degree intervals are aplurality of vane mounting pins 43 (see FIG. 5). These mounting pins maybe secured to the plate 40 by means of a countersunk screw 44 (also seeFIG. 5) extending from the bottom through the plate into threadedengagement with the mounting pin. Other suitable means (e.g., welding,etc.) may be employed to secure the mounting pin to the rotatable plate.As shown in FIG. 5, the tubular portion 42 of the vane 39 is slid overthe corresponding mounting pin 43 for engagement therewith. To restrictmovement of the vanes, there are provided circumferentially about theperiphery of the support plate 25 a 47. As shown in FIG. 3.,whichillustrates one position of the vanes, the rotatable plate 40 can bemoved in a counterclockwise direction. FIG. 3 illustrates the extremeouter and inner positions of rods 46, 47 respectively. The swirl vanes39 in FIG. 3 are disposed for imparting a counterclockwise spinningmotion to the secondary air. In the embodiment shown the spinning mo- Ition of the secondary air is in the same direction (counterclockwise) asthat of the primary vortex air flow. However, it is to be understoodthat .the disposition of the swirl vanes can be such as to impart acountercurrent spinning motion (which in the illustrated embodimentwould be clockwise) to the secondary air flow opposite that of theprimary vortex air flow. Each of the push rods 46 and 47 is mounted in asimilar manner and thus only the mounting of one is necessary for anunderstanding of that particular feature of the present invention. Theexternal or outer end of each push rod is provided with a manuallyengagable member disposed perpendicular to the lengthof the rod. Theinner end of each push rod is secured to a fastening member 48 whichextends radially outward from the rotatable plate I 40. The member 48can be secured to the plate 40 by 7 illustrates that the inner end ofthe push rod is secured by conventional means generally designated 49,

which may comprise nuts and bolts, to the fastening member 48. Tofacilitate sliding movement of the push rod through the burner casing 12and the interior insulation 13, there is provided anopening in thecasing 12 and the insulation 13, in which is mounted a tubular couplingmember 49. The coupling 49 is secured to the burner casing by means of aweld such as shown at 50. As shown in FIG. 3, the push rod 46 isdisposed in its outermost position, while the push rod 47 is disposed inits innermost position. FIG. 4 shows the push rod 46 urged inwardly andthe corresponding movement of the push rod 47 would be outward (notshown). While the swirl vanes 39 have been disclosed in the preferredembodiment as being moveable in order to provide variations in thespining motion imparted to the secondary air flow, it is within thescope of this invention to mount the plate 40 and swirl vanes 39 in astationary fashion.

Although not illustrated herein, it is also within the scope of theinvention to provide a plurality of air gaps for providing amultiplicity of secondary air flows whereupon suitable swirl vanes suchas described heretofore may be associated with each of the air gaps forimparting a spinning or swirling motion to all the auxiliary air flow.Alternatively, a single structure may be provided to impart thisspinning motion to each of the multiple auxiliary air flows. Variousconfigurations which might employ a plurality of auxiliary air flows aredisclosed in the heretofore mentioned copending U.S. application.

According to the present invention there has been provided a burner thatobviates the need for a combustion chamber while simultaneouslyproviding for substantially improved flame performance and qualitythrough precise flame control. Although there has been disclosed hereina preferred construction and arrangement of a burner, it should beunderstood that such disclosure is intended to be representative of apreferred embodiment only and that various changes may be made thereinwithout departing from the clear teachings of the present inventions.Thus, for example, although a single air gap has been described andillustrated, it is within the scope of the invention to employ ness, itis possible to achieve the desired results either with an arrangementincluding a single air gap or a plurality of air gaps which can rangefrom a horizontal air gap to an air gap disposed at substantially 45relative to the horizontal and for obtaining substantially longer flamesthe air gap may be disposed from substantially relative to thehorizontal to a vertical air gap. Accordingly, reference should be madeto the following appended claims in determining the full scope of theinvention.

Having thus set forth the nature of the invention, what is claimedherein is:

l. A chamberless staged-air vortex burner for use in the burning offuels and adapted to be mounted in a furnace wall having an openingtherein comprising in combination, burner casing means having an airinlet adapted for receiving an inlet air flow, air induction chambermeans having an outlet and being mounted within said burner casing forreceiving a predetermined portion of said inlet air flow and producing ahelical vortex primary air flow from said outlet, refractory meansmounted in said casing about said chamber outlet, said refractory meansincluding a substantially divergent surface extending outward from theperiphery of said outlet to a plane common with the outer surface ofsaid furnace wall, air gap means adapted to receive the remainingportion of said inlet air flow, said air gap means comprising at leastone air gap of substantially uniform annular configuration extendingthrough said refractory means and located between said outlet and theplane of said outer surface of said furnace wall in which said burner isto be mounted, means for imparting spinning directional motion to atleast a part of the remaining portion of said inlet air flow as itenters said one air gap, said one air gap being angularly disposedrelative to the axis of said primary air flow for projecting spinningsecondary air flow in a convergent direction toward the primary air flowaxis to contain the flame envelope and obtain precise flame control andintimate mixing of fuel and air proximate the point of fuel injection.

2. A vortex burner according to claim 1 wherein said motion impartingmeans is located radially outward of said chamber outlet directlyadjacent the inlet to said one air gap.

3. A vortex burner according to claim 1 wherein said one air gap isangularly disposed to provide convergent upward air flow in an outwarddirection relative to said chamber outlet.

4. A vortex burner according to claim 1 including means for selectivelyadjusting the width of said one air gap.

5. A vortex burner according to claim 1 wherein said burner isconstructed and arranged such that said air induction means is adaptedto receive substantially 25 to 50 percent of said inlet air flow andsaid air gap means is adapted to receive the remaining portion of saidinlet air flow.

6. A vortex burner according to claim 1 wherein said motion impartingmeans comprises a plurality of movably mounted vanes for imparting adifferent spinning motion to said secondary air flow.

7. A vortex burner according to claim 1 wherein said motion impartingmeans are mounted stationarily.

8. A vortex burner according to claim 1 wherein said motion impartingmeans is arranged to spin the secondary air flow in the same directionas the primary air 9. A vortex burner according to claim 1 wherein saidmotion imparting means is arranged to spin the secondary air flow in acountercurrent direction to said primary air flow.

10. A vortex burner according to claim 1 wherein said motion impartingmeans comprises a rotatable plate means located radially outward of saidchamber outlet proximate the inlet to said one air gap, spin vanemounted on said rotatable means. 1

11. A vortex burner according to claim 10 including means for guidingsaid rotatable plate means upon movement thereof.

12. A vortex burner according to claim 10 wherein said spin vanes aremounted for pivotal movement on said rotatable plate means, andincluding guide means associated with each of said spin vanes forlimiting the movement thereof.

l3. A vortex burner according to claim 10 including manually engageablemeans operably secured to said rotatable plate means for facilitatingmovement thereof.

14. A chamberless staged-air vortex burner for use in the burning offuels and adapted to be mounted in a furnace wall having an openingtherein comprising in combination, burner casing means having an airinlet adapted for receiving an inlet air flow, air induction chambermeans having an outlet and being mounted within said burner casing forreceiving a'predetermined portion of said inlet air flow and producing ahelical vortex primary air flow from said outlet, a support platesecured radially about said chamber means and extending radially outwardtherefrom, refractory means mounted on said support plate about saidchamber outlet, said refractory means including a substantiallydivergent surface extending outward from the periphery of said outlet toa plane common with the outer surface of said furnace wall, air gapmeans adapted to receive the remaining portion of said inlet air flow,said air gap means comprising at least one air gap of substantiallyuniform annular configuration extending through said refractory meansand located between said outlet and the plane of said outer surface ofsaid furnace wall in which said burner is to be mounted, an annularmember disposed on said support plate outward of said refractory means,spin vanes mounted on said annular member about said chamber means forimparting spinning motion to at least part of the remaining portion ofsaid inlet air flow, means for restricting movement of said annularmember, said one air gap being angularly disposed relative to the axisof said primary air flow for projecting spinning secondary air flow in aconvergent direction toward the primary air flow axis to contain theflame envelope and obtain precise flame control and intimate mixing offuel and air proximate the point of fuel injection.

15. A chamberless staged-air vortex burner for use in the burning offuels and adapted to be mounted in a furnace wall having an openingtherein comprising in combination, burner casing means having an airinlet adapted for receiving an inlet air flow, air induction chambermeans having an outlet and mounted within said burner casing forreceiving a predetermined portion of said inlet air flow and producingan uninterrupted helical vortex primary air flow from said outlet,refractory means including a substantially divergent surface extendingoutward from the periphery of said I outlet to a plane common with theouter surface of said furnace wall, air gap means adapted to receive theremaining portion of said inlet air flow, said air gap means comprisingat least one air gas of substantially uniform annular configurationextending through said refractory means and located between said outletand the plane of said outer surface, means for imparting spinningdirectional motion to at least part of the remaining portion of saidinlet air flow as it enters said one air gap, said one air gap beingangularly disposed relative to the plane of said outer surface forprojecting spinning secondary air flow in an outward direction relativeto said outlet of said induction chamber for containment of the flameenvelope, whereby intimate mixing of fuel and air is obtained proximatethe point of fuel injection.

16. A vortex burner according to claim 1 wherein said one air gap isdisposed angularly relative to the plane of said outer surface of saidfurnace wall.

* III

1. A chamberless staged-air vortex burner for use in the burning offuels and adapted to be mounted in a furnace wall having an openingtherein comprising in combination, burner casing means having an airinlet adapted for receiving an inlet air flow, air induction chambermeans having an outlet and being mounted within said burner casing forreceiving a predetermined portion of said inlet air flow and producing ahelical vortex primary air flow from said outlet, refractory meansmounted in said casing about said chamber outlet, said refractory meansincluding a substantially divergent surface extending outward from theperiphery of said outlet to a plane common with the outer surface ofsaid furnace wall, air gap means adapted to receive the remainingportion of said inlet air flow, said air gap means comprising at leastone air gap of substantially uniform annular configuration extendingthrough said refractory means and located between said outlet and theplane of said outer surface of said furnace wall in which said burner isto be mounted, means for imparting spinning directional motion to atleast a part of the remaining portion of said inlet air flow as itenters said one air gap, said one air gap being angularly disposedrelative to the axis of said primary air flow for projecting spinningsecondary air flow in a convergent direction toward the primary air flowaxis to contain the flame envelope and obtain precise flame control andintimate mixing of fuel and air proximate the point of fuel injection.2. A vortex burner according to claim 1 wherein said motion impartingmeans is located radially outward of said chamber outlet directlyadjacent the inlet to said one air gap.
 3. A vortex burner according toclaim 1 wherein said one air gap is angularly disposed to provideconvergent upward air flow in an outward direction relative to saidchamber outlet.
 4. A vortex burner according to claim 1 including meansfor selectively adjusting the width of said one air gap.
 5. A vortexburner according to claim 1 wherein said burner is constructed andarranged such that said air induction means is adapted to receivesubstantially 25 to 50 percent of said inlet air flow and said air gapmeans is adapted to receive the remaining portion of said inlet airflow.
 6. A vortex burner according to claim 1 wherein said motionimparting means comprises a plurality of movably mounted vanes forimparting a different spinning motion to said secondary air flow.
 7. Avortex burner according to claim 1 wherein said motion imparting meansare mounted stationarily.
 8. A vortex burner according to claim 1wherein said motion imparting means is arranged to spin the secondaryair flow in the same direction as the primary air flow.
 9. A vortexburner according to claim 1 wherein said motion imparting means isarranged to spin the secoNdary air flow in a countercurrent direction tosaid primary air flow.
 10. A vortex burner according to claim 1 whereinsaid motion imparting means comprises a rotatable plate means locatedradially outward of said chamber outlet proximate the inlet to said oneair gap, spin vanes mounted on said rotatable means.
 11. A vortex burneraccording to claim 10 including means for guiding said rotatable platemeans upon movement thereof.
 12. A vortex burner according to claim 10wherein said spin vanes are mounted for pivotal movement on saidrotatable plate means, and including guide means associated with each ofsaid spin vanes for limiting the movement thereof.
 13. A vortex burneraccording to claim 10 including manually engageable means operablysecured to said rotatable plate means for facilitating movement thereof.14. A chamberless staged-air vortex burner for use in the burning offuels and adapted to be mounted in a furnace wall having an openingtherein comprising in combination, burner casing means having an airinlet adapted for receiving an inlet air flow, air induction chambermeans having an outlet and being mounted within said burner casing forreceiving a predetermined portion of said inlet air flow and producing ahelical vortex primary air flow from said outlet, a support platesecured radially about said chamber means and extending radially outwardtherefrom, refractory means mounted on said support plate about saidchamber outlet, said refractory means including a substantiallydivergent surface extending outward from the periphery of said outlet toa plane common with the outer surface of said furnace wall, air gapmeans adapted to receive the remaining portion of said inlet air flow,said air gap means comprising at least one air gap of substantiallyuniform annular configuration extending through said refractory meansand located between said outlet and the plane of said outer surface ofsaid furnace wall in which said burner is to be mounted, an annularmember disposed on said support plate outward of said refractory means,spin vanes mounted on said annular member about said chamber means forimparting spinning motion to at least part of the remaining portion ofsaid inlet air flow, means for restricting movement of said annularmember, said one air gap being angularly disposed relative to the axisof said primary air flow for projecting spinning secondary air flow in aconvergent direction toward the primary air flow axis to contain theflame envelope and obtain precise flame control and intimate mixing offuel and air proximate the point of fuel injection.
 15. A chamberlessstaged-air vortex burner for use in the burning of fuels and adapted tobe mounted in a furnace wall having an opening therein comprising incombination, burner casing means having an air inlet adapted forreceiving an inlet air flow, air induction chamber means having anoutlet and mounted within said burner casing for receiving apredetermined portion of said inlet air flow and producing anuninterrupted helical vortex primary air flow from said outlet,refractory means including a substantially divergent surface extendingoutward from the periphery of said outlet to a plane common with theouter surface of said furnace wall, air gap means adapted to receive theremaining portion of said inlet air flow, said air gap means comprisingat least one air gas of substantially uniform annular configurationextending through said refractory means and located between said outletand the plane of said outer surface, means for imparting spinningdirectional motion to at least part of the remaining portion of saidinlet air flow as it enters said one air gap, said one air gap beingangularly disposed relative to the plane of said outer surface forprojecting spinning secondary air flow in an outward direction relativeto said outlet of said induction chamber for containment of the flameenvelope, whereby intimate mixing of fuel and air is obtained proximatethe point of fuel injectioN.
 16. A vortex burner according to claim 1wherein said one air gap is disposed angularly relative to the plane ofsaid outer surface of said furnace wall.